The publishers are certainly gouging the public when they charge over $12 for a kindle edition that costs a few cents to produce and distribute (marginal cost obviously) but it is not Amazon's fault and they should not be blamed. The publishers and Apple got together and agreed to fix prices. Some of them are now being sued in the US and the UK for this. Personally, when I find a kindle edition that is higher priced than the physical book I buy a second hand copy or borrow it from the library and then send an email to the publisher saying "that's what you get for being greedy. A hundred percent of zero is zero." If enough of us do this they may realise that their greed is going to cost them in the longer run; already some authors are realising that this pricing model is not in their interest and are publishing directly online.